A sectional view of a related-art lawn mower 101 is shown in FIG. 9. A motor 112 is fixed to a chassis 102, which is a basic framework of the lawn mower 101, in such a manner that a rotation shaft of the motor is positioned in a vertical direction. By transmitting the power of the motor 112, a rotary blade 122 is rotated. A fixed blade 124 which is fixed to a lower end of a fixed shaft 118 is positioned below the rotary blade 122. A pinion is fixed to an output shaft 112a of the motor 112, and by transmitting a rotation force of this pinion to a gear 116, a fitting member 120 which is connected to a lower side of the gear 116 is rotated. The fitting member 120 is held so as to rotate around the fixed shaft 118, and is pressed downward by a spring 127, and accordingly, the rotary blade 122 is constantly urged toward the fixed blade 124. When the rotary blade 122 is rotated, lawn is mown by a combination of the rotary blade 122 and the fixed blade 124. Such structure of the lawn mower 101 is disclosed, for example, in JP-A-S59-59113.
In the related-art lawn mower 101, a large noise occurs when the rotary blade 122 and the fixed blade 124 are rubbed against each other. At the same time, vibration which occurred from the rubbing between the rotary blade 122 and the fixed blade 124 is transmitted to the chassis 102 and a body cover 103, by way of the rotary blade 122 and the fixed shaft 118. As a result, the chassis 102 and the body cover 103 are vibrated, and a large noise may occur, due to the vibration of the chassis 102 and the body cover 103.